# testo Smart — user reviews > 152 indexed App Store user reviews of testo Smart by Testo SE & Co. KGaA, rated 2.70/5 from 165 ratings. - Source: https://appshunter.io/ios/app/testo-smart/id1482139629/reviews - App overview in markdown: https://appshunter.io/ios/app/testo-smart/id1482139629.md - Rating breakdown: 5★ 38 · 4★ 22 · 3★ 21 · 2★ 22 · 1★ 62 ## What do users think of testo Smart? Overall sentiment: negative **Pros** - 👍 Good app with some features - 🚀 Great product - 🚀 Useful app for measurements **Cons** - 🐛 App won't connect - 🐛 Connectivity issues - 🐛 Unreliable connection - 🐛 Forced updates - 🐛 Laggy and unresponsive UI - 🐛 Crashes and bugs - 🐛 Doesn't work as expected - 🐛 Poor app design and functionality **Commonly reported bugs** - App won't connect to devices - Compatibility issues with newer iOS versions - Frequent crashes and freezes - Inability to save favorite refrigerants - Measurement data not displaying properly **Most requested features** - Add option to toggle Bluetooth discovery - Improve Bluetooth range - Add ability to customize colors and graphs - Improve data export functionality - Add option to name sensors - Improve multi-probe support - Integrate more features from physical devices ## Newest reviews (16 of 152) ### 2/5 — Testo 550s @ Apple *2026-08-21, version 31.31.31* we recently began using the 550S combined with the smart app. While the 550s works very well as a stand alone manifold the app is doesn’t generate reports or show the pressures at the top of the screen. The only work around we have found is screen recordings if you’re using iPad or an iPhone. The pressures are shifted to the bottom of the screen into small blocks. The lack of its ability to generate reports is a deal breaker for us. The app does not work as advertised. It’s a shame really the instrument it’s self works great. If your team requires proof prior to new unit commissioning. This app is not for you. ### 3/5 — Paul *2026-06-05, version 31.31.21* This app could be soooooo good yet it falls down on the basics . I use it for lev testing of dust drops and There is nowhere to put a drop number. You have to put it in the information. Which ok at least it’s in the paperwork. But then you go back to the list and it only shows the customer time and date in the list NO information. So I spend hours trying to search for pod 10 out of 50 pods. It’s so frustrating. The only way to get around it is to export and name each file after a pod but if you name one wrong or miss one, you try find it in the list? Such a shame. It just doesn’t let you rename a save file and save it in the app. That’s all it needs to do ### 3/5 — Einloggen *2026-06-01* ☹️Es nervt einen nach jeden Ende meldet sich die App automatisch ab. Ständiges Einloggen macht keinen Sinn. Es wäre auch sinnvoll diese App im offline Modus zu benützen. Wenn man solche teuern Geräte von Testo kauft erwartet man auch eine 100% App dazu . ### 2/5 — Is anyone actually working on this?! *2026-05-01, version 31.31.20* This has to be the worst app for refrigeration I have ever used. Do the developers actually use the stuff they produce?! There's no way to pre configure which data is displayed on the graphics?! Are you kidding me?! Do you know how much time I have wasted researching high pressure, sub cooling, and liquid line temperature because the stupid defaults are useless to me?!? This is beyond frustrating. Every other app I have used for other manufacturers tools is more configurable and makes sense from a technicians perspective. The testo hardware itself is great-- this app makes me regret ever buying it though! I wish I knew the Bluetooth protocols involved -- I bet I could vibe code a replacement that blows this app away in a weekend. ### 4/5 — Super outils *2026-03-24* Génial pour observer et pouvoir analyser le fonctionnement. Un point qui pourrait être intéressant, pour les sondes de pression, c’est d’avoir les températures avec les pressions d’affichées. Ça concerne les sondes 549i. En application froid, elle affiche une pression seulement. **Developer response:** Bonjour, merci beaucoup pour votre évaluation 4 étoiles, cela nous fait vraiment très plaisir. Quelles sondes et quel programme de mesure utilisez-vous exactement dans l'application ? Votre équipe Testo App ### 4/5 — Good App with some work *2026-02-26, version 30.2.16* This is a really handy app, I just wish they would tidy up the customers and measurements sites portion of it. You cant see measurements when you go into customers section, and it easily gets messy trying to save several measurements for different boilers or extracts on the same site. Constantly going back and forth between customers and saved data. If this was sorted I’d give it 5 stars. ### 4/5 — Tightness Test Protocol *2026-02-10, version 30.2.7* Hi, I really like the app and how it connects to my flue analyser and I use the smart probes to perform tightness testing, however the let by test sequence is in another protocol and not incorporated into the tightness test section, can this be incorporated in an update with the option to skip let by if already passed? Thanks, Chris ### 3/5 — Testo App iPhone *2026-02-03, version 30.2.7* Hi guys, since you updated (few months ago) so frustrating that every time I open the app im confronted with a splash screen suggesting to download the ‘NEW TESTO SMART APP’ Seriously im up to date, so why dont you program the app to check its version and if its the latest, then bypass this screen. If this is happening to all uses there must be a lot of other frustrated users globally! Please fix. Also do you think there may be a way to increase the ability for Testo blue tooth devices to have a bit more range? So frustrating moving only a few meters from gauges to be disconnected. Additionally almost always after disconnect I need to close the app and restart 🙄 loosing any data I may require. These tools are not cheap, please try to show some sense of pride in your R&D and fix these oversights. ### 3/5 — “Smart” *2026-01-21, version 30.2.7* It’s not, really. The app, for tightness testing, doesn’t work anything like what is expected in standards or ACOP. Excellent for dynamic pressure testing in awkward places, however. ### 2/5 — Painful to use *2025-12-28, version 30.2.7* Testo smart app is a pain to use. I don’t understand why every time you use the app it has to download again. This never use to be this way. ### 3/5 — Klappt nicht immer *2025-11-25* Benutze es zum speichern der Abgasmesswerte. Was ich sehr gut finde da ich die Berichte per Mail an den Kunde schicke und ich so die Messwerte auch mit schicken kann. Nur leider klappt zur Zeit als fast nicht die Verbindung. Beim öffnen der App wird nach der Verbindung gefragt und dann tut sich Nix mehr, am IPad zeigt es das wlan an. Aber es kommt keine Verbindung zustande. Was sehr schade ist. Habe mir extra das testo gekauft das ich sie Funktion habe. Hoffe es klappt beim nächsten Update wieder besser ### 1/5 — Ne tient pas ses promesses *2025-11-20* Débit volumétrique ne fonctionne pas ### 1/5 — “Smart” *2025-11-01, version 30.2.7* It’s not, really. The app, for tightness testing, doesn’t work anything like what is expected in standards or ACOP. You will waste approx three times test periods trying to get it zeroed and then it’ll start before pressure can be introduced. Only if there’s nothing wrong with the equipment, of course which proved as reliable as the app. ### 3/5 — Kann sich nicht verbinden *2025-10-14* Kann sich leider nicht mit der neuen iOS Version 26 verbinden stellt zwar das wlan her aber trotzdem keine Verbindung. Mit testo 300. und testo 510i ist nicht zulässig in der testo smart App. Leider können wir keines von den Messgeräten wie vor her benutzen bei dem Preis für die Geräte könnte man mehr erwarten. **Developer response:** Hallo, könnten Sie uns bitte eine E-Mail an appsupport@testo.de schreiben damit wir gemeinsam eine Lösung für das Verbindungsproblem finden können? Ihr Testo App Team ### 1/5 — Terrible *2025-10-08, version 30.2.7* They keep “updating” the app and I barely recognize it anymore. It’s so difficult to navigate and is full of bugs. I actually bought Fieldpiece guages and started switching all my tools over. I will be selling my Testo equipment. ### 1/5 — Second screen doesn’t work after latest update *2025-10-03, version 30.2.7* Second screen hasn’t worked in months since this app updated. Selling my testo. Buy a Seitron way higher quality and always works ## Most critical reviews (10 lowest-rated) ### 1/5 — App ist nicht einwandfrei! *2026-05-27* Das Messgerät an sich ist super wenn man den Akku mal außer Betracht lässt . Allerdings die App ist eine reine Katastrophe. Wie schon öfters hier beschrieben verbindet sich das Messgerät nur nach mehrmaligen An und Ausschalten mit der App . Da wir ein Fachbetrieb sind und uns für das Produkt entschieden hatten ist es für uns umso ärgerlicher ,dass das Digitalisieren nur erschwert möglich ist . Warum nur einen Stern vergeben wird hat den Hintergrund , dass man beim Service nicht für Ernst genommen wird und Aussagen getätigt werden wie „ Dies ist uns nicht bekannt versuchen Sie die App auszulagern und wieder zu installieren „ . Da fragt man sich lesen Sie ihre eigenen Bewertungen nicht ?! Als letzten Versuch waren wir beim Testo Stand auf der SHK Messe dort wurde genau dasselbe von sich gegeben . „So etwas wäre nicht bekannt man wird belächelt und man könne nicht weiterhelfen ! „ Absolute Frechheit meiner Meinung nach ein Unfertiges Programm bzw. App auf den Markt zu bringen !! Ich hoffe sehr ,dass es bald ein Update gibt und die Probleme behoben werden ! ### 1/5 — Does not work with the testo 300 *2026-05-04, version 31.31.20* Maybe this app works with other devices but it does not work with the testo 300 ### 1/5 — Favorites 557s *2026-04-15, version 30.2.16* Changing favorite refrigerants doesn’t “stick”. You remove one and it just goes back to a favorite. Since you can only have 5 I can’t add any which means I spend a ton of time on jobs scrolling through refrigerants. Restore to factory settings on the gauges retains the favorites from the app (with the app closed and phone not connected). I wanted to get something better but guy on marketplace that wanted to buy them has the same problem and I refunded him because he claims the product (or app) is defective. ### 1/5 — App won’t connect *2026-03-05, version 30.2.16* I have a new set of 557s and the app won’t connect. Used to work fine. I first posted this in June of 2025, now it’s March of 2026. Both the Gauges and iPhone have the latest updates. Still doesn’t work. And no it doesn’t show up in the available to connect list, everything else does. The probes connect, old gauges connect. Testo has gone down hill. ### 1/5 — Worst *2026-02-25, version 30.2.16* Very bad update; didn’t expect that from Testo ### 1/5 — Sign in limited use *2026-02-25, version 30.2.16* This app is horrible I hardly use them it says limited use only there is nowhere on app settings for what it asks for even after updating ### 1/5 — In app purchases now *2026-01-14, version 30.2.7* Bought the whole kit for refrigeration and hvac measurements that were already very expensive to begin with. One of the most handy features was being able to do CFM readings with the hot wire anemometer. Go to do one today and find out I now need to subscribe monthly or yearly to be able to use that feature of the tool. Will be selling the probes and buying a different brand standalone for these measurements. ### 1/5 — Business owner *2026-01-11, version 30.2.7* I connect my new Testo 410i anemometer to the app when it actually decides to connect and proceed to preform a duct flow scan. The software then alerts me to first connect to a device while simultaneously showing me velocity and temp readings from the device I’m already connected with. On one occasion (after many attempts) the software actually allowed me to proceed to the scan but this is in no way repeatable. This may be a case where a good product is ruined by horrible software. ### 1/5 — New User *2025-12-21, version 30.2.7* This app is not Smart in my opinion and the support has been poor as well. I have been using it for balancing air systems and not worth the money ! Zero stars no an option so one star from me until they sort out some fundamentals and their marketing ! ### 1/5 — No more “temperature IR”? *2025-12-17, version 30.2.7* Got given a testo 805i as a gift, extremely excited to use if for surface temp measurements and pictures as is described in every app tutorial that hasn’t been updated in the last 9 years, only to open the app and have no temperature IR setting available to allow me to take measurements and pictures. ## Most praised reviews (10 highest-rated) ### 5/5 — Chiller tech *2026-07-11, version 31.31.31* Are you guys going to add refrigerant R-514 for the new low pressure centrifugals? Please add it Thank you ### 5/5 — Works as it should *2026-06-13, version 31.31.21* Good app and love my 558s. Haven’t had an issue with app, gauges, probes, micron gauge, etc.. glad I went testo over fieldpiece ### 5/5 — More like this please *2026-06-09, version 31.31.21* I needed a handheld air flow meter that allowed for a wide range to verify built in instrumentation. Feel like I found gold in the 510i manometer. It has no screen, only a light and a button. All readings feed through this app which i configure and feed identifiers to. The exported csv files include everything making my documentation work easy as can be. I don’t know why i need one of these manometers for home, but i want one. Probably should avoid looking at FLIR tools while i still have a checking balance. ### 5/5 — Super application *2025-10-15* J’aimerais voire une application pour Apple Watch sa serait cool de pouvoir suivre c est les pressions directement depuis la montre **Developer response:** Bonjour, wow, un grand merci pour votre évaluation 5 étoiles — cela nous fait vraiment très plaisir. Nous avons transmis votre idée d’une application pour l’Apple Watch à notre équipe de gestion de produit. Votre équipe Testo App ### 5/5 — Apple Watch *2025-06-18* Bitte Version für Apple Watch rausbringen **Developer response:** Hallo, wow, vielen Dank für die 5-Sterne-Bewertung, das freut uns wirklich sehr! 😊 Eine Version für die Apple Watch ist aktuell leider nicht geplant, da die Nachfrage derzeit noch recht gering ist. Aber wir nehmen Ihren Wunsch gerne auf unsere Liste für zukünftige Entwicklungen auf. Vielen Dank für Ihr Feedback! Ihr Testo App Team ### 5/5 — Love this app and the tools, One problem though… *2025-03-17, version 28.13.7* I am a commercial/industrial chiller technician, and I use my testos daily. Absolutely love them, have had them since I first got in the field. However, recently I am noticing that the saturation temperature is displayed at the bottom of the UI, on its own tab now. Instead of directly under the pressure reading. Not sure if it is a bug or new addition, however I’m severely concerned. This makes referencing less easier and less comfortable than it used to be, and I would love to see it be able to be toggled, or removed. ### 5/5 — No good anymore! *2024-08-22* What happened to the refrigeration gauges?? They stop working on the app. My testo probes won’t connect to the add button on the gauges., sure they will connect to the app but all the vital information disappeared from screen. I can only read pressures and temperature. Where is the conversion into SH or SC and the other parameters? What you guys are doing? This supposed to be one of the best apps out there and now I can’t even use my probes witch I paid dearly for! **Developer response:** Hi, it would help us a lot if you could write us an e-mail (appsupport@testo.de) so that we can try to find out together why the connection is not working at all. Best regards, Your Testo App Team ### 5/5 — Great Product *2023-10-27, version 20.9.12* Really great app integration to an awesome piece of smart guages. Will recommend to all, 100% 👍 ### 5/5 — Top Funktionen & stabil *2023-04-09* Nutze die App als Second screen mit meiner Monteurhilfe 557s, zur Dokumentation und zwischendurch für den schnellen Check der Anlage mit den Smart probes 115i und 552i. Echt hilfreich, mittlerweile auch stabil und ständig neue Funktionen. **Developer response:** Hallo, wow, vielen Dank für die 5-Sterne-Bewertung, das freut uns wirklich sehr. Falls Sie eine Idee haben, was wir vielleicht noch besser machen können, schreiben Sie uns gerne 😉. Ihr Testo App Team ### 5/5 — Multi tasking *2023-02-01, version 15.11.9* Just like most things. Once you get used to it, it’s very good. I would say more precise options and measurements than the field piece. --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-01.*