LOCK MEMO vs Volt Drop Check & Plug
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
LOCK MEMO
This app offers a straightforward way to create and manage private notes with robust passcode protection. It's designed for intuitive use, requiring no complex setup to keep your personal information, ideas, and daily entries secure and organized.
- Passcode protection
- Create and edit notes
- Folder management
- Search notes
- iCloud backup
- Adjustable font size
Read full descriptionHide full description
LOCK MEMO is a simple and secure note app with password protection. Designed with simplicity in mind, anyone can use it intuitively without complicated steps. No complex setup is required. Start using it today. ※ Password protection must be enabled in settings. ** Features ** • Create and edit notes • Passcode protection • Adjust font size • Character and line counter • Search notes • Folder management • iCloud backup • URL scheme (pwmm:) Perfect for storing private information, ideas, daily notes, and personal content securely. Keep your notes safe and organized with LOCK MEMO. ■ Terms of Use https://eeggs.jp/terms-of-use-en
Volt Drop Check & Plug
Read full descriptionHide full description
Volt Drop Check & Plug is an iPhone-only electrical calculation toolkit for field electricians, maintenance technicians, and design engineers. Stop juggling paper tables, calculators, and spreadsheets — switch between tabs and get the answer you need in seconds. ■ What's inside 1) Voltage Drop Calculator • Inputs: supply voltage, load current (or power in W), cable length, conductor material (copper / aluminum), insulation (PVC 70°C, XLPE 90°C, heat-resistant PVC 105°C), circuit type (DC / 1-phase 2-wire, 3-phase 3-wire), power factor, and optional reactance. • Outputs: ΔV, drop %, terminal voltage, loop resistance, and assumed conductor temperature. • GOOD / CAUTION / NG verdict badge with a one-line explanation, improvement suggestions, risk notes, and basis notes. • Round-trip ×2 applied automatically for DC / single-phase; √3 factor applied for three-phase. 2) Cable Size Selection (reverse calculation) • From load current, voltage, cable length, allowable drop %, material, circuit type, power factor, and ambient temperature, get the minimum required conductor area and a recommended cable size. • Side-by-side comparison of common sizes with PASS / FAIL / BEST indicators. 3) Ampacity Calculator • From conductor material, size, installation method (free air / in conduit / bundled), insulation type, ambient temperature, and grouping count, see base ampacity with temperature and grouping correction factors. • Corrected ampacity plus a per-installation-method summary. 4) Breaker Selection Guide • From circuit current, circuit voltage, usage (general load / motor / lighting / IT·server), and phase (single / three), get a recommended rating (AT), frame size (AF), and type (MCCB / MCB / ELCB). • Earth-leakage (ELCB) recommendation is highlighted automatically where appropriate. Includes a type guide. 5) Power Calculator (W ↔ VA ↔ kVA ↔ var) • Convert between active power (W / kW), apparent power (VA / kVA), reactive power (var / kvar), and phase angle φ from voltage, current, and power factor. • Three input modes: V×A, W, or VA. Single-phase / three-phase switchable. 6) NEMA / IEC Plug Quick Reference • A searchable cheat sheet for plugs and connectors — useful for overseas sites and imported equipment. Filter by code, voltage, and more. ■ Designed for the field • One-tap Japanese / English UI toggle (selection is remembered). • All calculations run on-device — works reliably even with poor signal. • Clear separation of inputs and results, with verdict badges and plain-language notes. • iPhone-first layout tuned for one-handed use. ■ Great for • Field electricians and contractors • Facility and maintenance technicians • Plant and building-services engineers • Solar, energy-storage, and EV-charging designers • Teams working with imported or overseas equipment • Electrical students and trainees ■ Important Results are reference values based on generic targets (e.g., 3% voltage-drop goal, 5% maximum). Always follow your local codes, internal standards, and equipment specifications for actual design and installation.
Screenshots
Verdict
The clearest difference is price: LOCK MEMO at Free against Volt Drop Check & Plug's $0.49. LOCK MEMO also leads on update cadence (monthly vs every 7 months). Volt Drop Check & Plug's advantage is in-app purchases (none vs 1) and ads (none vs shown). On 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
LOCK MEMO is free to download; Volt Drop Check & Plug costs $0.49 up front. LOCK MEMO sells 1 in-app purchase, starting at $0.99 per month. Volt Drop Check & Plug asks for nothing beyond the download.
LOCK MEMO ships an update monthly, Volt Drop Check & Plug every 7 months. The most recent releases landed on October 17, 2026 and October 2, 2026 respectively.
| Parameter | LOCK MEMO | Volt Drop Check & Plug |
|---|---|---|
| Price | Free — better | $0.49 |
| Rating | 4.7 (495 ratings) — better | — |
| Positive reviews | 74.5% of reviews | — |
| Number of ratings | 495 — better | — |
| Update frequency | Monthly — better | Every 7 months |
| Ads | Yes | No — better |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone | iPhone, iPod — better |
| Requires iOS | 17.0 | 15.1 — better |
| Further details — not scored | ||
| Size | 33 MB | 35 MB |
| Age rating | 4+ | 4+ |
| Developer | EasterEggs | MASAHIRO HIRAIWA |
Bugs and requests
LOCK MEMO
Reported bugs
6 issues- Notes disappearing from folders
- Edit function becomes unavailable
- App incompatible with newer iOS versions
- Touch ID not functioning despite advertised
- Password recovery issues
Show 1 moreShow fewer
- App crashes or freezes
Requested features
9 requests- Alphabetical sorting of notes
- Search functionality
- Touch ID/biometric authentication
- Text formatting options (bold, underline, italics)
- Ability to share or export notes
Show 4 moreShow fewer
- Picture upload capability
- Increased storage space
- Option to purchase ad-free version
- Dark mode option
Volt Drop Check & Plug
Not enough reviews yet to summarise bugs or requests.
In-app purchases
LOCK MEMO
- Premium Plan$0.991 Month
Volt Drop Check & Plug
No in-app purchases
Questions
Is LOCK MEMO free?
Is Volt Drop Check & Plug free?
Do LOCK MEMO or Volt Drop Check & Plug have ads?
Which is updated more often, LOCK MEMO or Volt Drop Check & Plug?
Other comparisons















