Key vs NFC TagKit
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Key
Transform your iPhone into a mobile ID card for convenient door access. Securely register your credentials and use your phone to open doors, leveraging advanced encrypted transfer technology.
- Smartphone as mobile ID
- Convenient door opening
- Secure credential transfer
- iPhone integration
- Requires Interflex software
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Your smartphone as a mobile ID card: With the Interflex app "Key", you can conveniently open doors with your iPhone. This is how "Key" works: - Install the app on your iPhone. - Register the app with your access data. - Book with your iPhone to open doors. Thanks to "NetworkOnMobile" technology, we ensure encrypted and secure transfer of the mobile credential to your iPhone. Important: The use of this app requires the use of the Interflex software IF-6040 and suitable badge readers.
NFC TagKit
This app allows you to read and write data to various types of RFID tags. It can display detailed information about transponders and supports creating and writing NDEF records on MIFARE® DESFire® tags.
- Read transponder information (type, manufacturer, serial number)
- Display NDEF record data (URL, text, contact)
- Read data from MIFARE® DESFire® tags
- Write files and NDEF records on MIFARE® DESFire® tags
- Supports various tag types (MIFARE, Ntag, FeliCa, ISO)
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NFCTagKit is an application for working with RFID tags. It provides such functions as reading different kinds of transponders and writing on MIFARE® DESFire® tags. Activating a reading function of the application displays all necessary information about the transponders: • tag type and manufacturer • technologies • serial number • total memory size • filled data volume • etc. Besides that, there is all the information about NDEF records and all the data on the card for such formats as • URL • text message • contact information • etc. One of the key advantages is reading the data from MIFARE® DESFire® transponders, including applications, files, and keys. Activating a writing function of the app grants the possibility to use the demo of the CoreWillSoft GmbH solution. The users can create and write files on the MIFARE® DESFire® tags and make different types of NDEF records. The NFCTagKit App supports such types of tags, as: • MIFARE® DESFire® EV1 • MIFARE® DESFire® EV2 • MIFARE® Ultralight® • MIFARE® Ultralight® C • MIFARE® Ultralight® EV1 • Ntag 213 • Ntag 215 • ISO15693 • FeliCa • ISO7816 (ISO14443-4 type A / B tag with ISO7816 communication protocol) The full functionality of our solution is available for ordering on the CoreWillSoft GmbH website. We are providing the decisions for all kinds of businesses that use RFID technologies and mobile identification.
Screenshots
Verdict
The clearest difference is iOS requirement: NFC TagKit at 15.6 against Key's 17.0. On price, review sentiment, update cadence and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Both ship on a similar rhythm, roughly every 4 months. The most recent releases landed on September 14, 2026 and September 19, 2026 respectively.
| Parameter | Key | NFC TagKit |
|---|---|---|
| Price | Free | Free |
| Rating | — | 4.0 (1 ratings) — better |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | — | 1 — better |
| Update frequency | Every 4 months | Every 4 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPod, Apple Watch — better | iPhone, iPod |
| Requires iOS | 17.0 | 15.6 — better |
| Further details — not scored | ||
| Size | 18 MB | 8 MB |
| Age rating | 4+ | 4+ |
| Developer | Interflex Datensysteme GmbH | CoreWillSoft GmbH |
Customer experience
Key
NFC TagKit
In-app purchases
Key
No in-app purchases
NFC TagKit
No in-app purchases









