PDF Lock vs EnGrid
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
PDF Lock
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Forgot the password on an important PDF? Need to secure a document before sharing? PDF Lock: Unlock & Protect makes it simple — unlock or password-protect any PDF right on your iPhone or iPad, in just a few taps. Your files never leave your device. Everything is processed locally using Apple's built-in PDF engine. No uploads. No cloud. No account required. No ads. Just fast, private PDF security whenever you need it. UNLOCK PDFs IN SECONDS Remove password protection from any PDF and get back to reading, editing, or sharing. Enter the current password, and your unlocked file is ready to export — to Files, Mail, WhatsApp, or any app you use. LOCK PDFs WITH A PASSWORD Keep sensitive documents safe before you send them. Add strong password protection to any PDF so only the right people can open it. (PDF Lock is included with PDF Lock: Unlock & Protect Pro.) BUILT-IN PDF VIEWER Preview your unlocked or locked PDF inside the app before you export. Scroll through every page with a clean, full-screen viewer — no extra apps needed. EASY EXPORT & SHARE Save processed PDFs to the Files app or share them instantly with the native iOS share sheet. Your workflow stays simple and familiar. PDF HISTORY Revisit your recently processed files without hunting through folders. Open past PDFs directly from your history list and pick up where you left off. HOW IT WORKS 1. Select a PDF from Files, Mail, or any app 2. Unlock it (enter the password) or lock it (set a new one) 3. Preview, export, or share — done PRIVACY YOU CAN TRUST * 100% on-device processing — files are never sent to a server * No account or sign-up required * No ads, ever * Your passwords and documents stay on your device FREE TO START Get 2 free PDF unlocks every day — no credit card, no commitment. Perfect for occasional use. UPGRADE TO PRO Go unlimited with PDF Lock: Unlock & Protect Pro: * Unlimited PDF unlocks — no daily limits * Lock PDFs with password protection * Extended PDF history (last 20 files) * Priority support Download PDF Lock: Unlock & Protect today and take control of your PDF security — privately, quickly, and right from your pocket. Subscription automatically renews unless cancelled at least 24 hours before the end of the current period. Manage or cancel anytime in your App Store account settings. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
EnGrid
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EnGrid connects devices that use, produce or store larger amounts of electricity. It determines when it makes sense to use, produce or store just the right amount of electricity via utilising our AI Strategies. Enset Controller links solar power plants, energy storage systems, heat pumps, and electric chargers to the EnGrid system. It manages electricity production and consumption, adjusts power draw from the grid, and uses advanced algorithms to ensure cost-effective energy use and maximum self-sufficiency. Enset Gateway This extension of the EnGrid system converts RS485 serial signals into TCP/IP signals. It is used when the Enset Controller’s two RS485 inputs are insufficient or when the device’s distance makes cable connections impractical. Additionally, the Gateway can control third-party devices via two relay outputs, such as a heat pump using SmartGrid Ready (SG Ready) or an EVU contact. The Enset Converters capture billing measurement data from meters with specific outputs without the need of additional power. The P1 and P1 – WiFi model wirelessly connects meters like the Iskraemeco AM550 to your network via WiFi or cable. The I1 (M-Bus) – Cable model connects meters like the Landis+Gyr E350 and E450 to the Enset controller via a wired connection. We optimize: EnGrid connects devices that use, produce or store larger amounts of electricity. It determines when it makes sense to use, produce or store just the right amount of electricity via utilising our AI Strategies. Smart EV Charging: When you at your home or in work, your vehicle could and should be charged the way it gets the battery full for the lowest cost possible. This becomes even more important if your company owns and charges multiple vehicles. Demand Response: When there is too much electricity available on the market, the result in low or even negative energy prices. You can benefit by adapting your use or production of energy to match what the market needs: use less or more, depending on the time. Supported devices: EnGrid can connect to more than 250 devices across 50 brands. Keywords: Energy management system, EnGrid, Enset, peak shaving, peak shifting, demand side management, electricity, costs, bill, cut your costs, AI, artificial intelligence, zero-export, dynamic load management, ev charging, smart charging, energy control, electricity control, solar control, ev control, battery management, P1, smart grid, battery control, smart meter, reading data
Screenshots
Verdict
The clearest difference is in-app purchases: EnGrid at none against PDF Lock's 2. EnGrid also leads on iOS requirement (15.0 vs 17.6). PDF Lock's advantage is update cadence (fortnightly vs every 2 months). On price, ads and device support 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. PDF Lock sells 2 in-app purchases, starting at $0.99 per month. EnGrid asks for nothing beyond the download.
PDF Lock ships an update fortnightly, EnGrid every 2 months. The most recent releases landed on November 5, 2026 and October 31, 2026 respectively.
| Parameter | PDF Lock | EnGrid |
|---|---|---|
| Price | Free | Free |
| Update frequency | Fortnightly — better | Every 2 months |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.6 | 15.0 — better |
| Further details — not scored | ||
| Size | 17 MB | 46 MB |
| Age rating | 4+ | 17+ |
| Developer | Nikunj Gondaliya | Enset d.o.o. |
In-app purchases
PDF Lock
- Monthly - PDF Lock & Unlock Pro$0.991 Month
- Yearly - PDF Lock & Unlock Pro$7.991 Year
EnGrid
No in-app purchases









