Comparison

BlueGrays vs 555 Timer & Oscillators Pro

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

BlueGrays

Learn electronics with interactive projects, a component catalog, and personal inventory management. Start with free projects and unlock full access to Arduino, ESP32, and IoT content with a premium subscription. Gamified learning with badges and levels keeps you motivated.

Highlights
  • Free starter projects
  • Unlimited Arduino/ESP32/IoT projects
  • Detailed circuit diagrams and code
  • Component catalog with specifications
  • Personal inventory management
  • Gamified learning with badges and levels
  • Multi-language support
Features
Read full description

Learning electronics has never been this easy and fun with BlueGrays! Start with free projects right away, and unlock all content with Premium when you're ready. Whether you're a student or a hobbyist, BlueGrays gives you everything you need. — START FOR FREE — • Begin learning electronics with curated starter projects • Explore basic components and their specifications • Try the app and see if it's right for you — EXPLORE PROJECTS (Premium) — • Unlimited access to Arduino, ESP32, ESP8266 and IoT projects • Detailed circuit diagrams, code snippets, and video tutorials for each project • See required components and add missing ones to your inventory • Rate projects and save your favorites • Track your completed projects — COMPONENT CATALOG (Premium) — • Full access to extensive electronic component database • Detailed specifications and use cases • Filter, sort, and easily find what you need • Add components directly to your inventory — MY WORKSHOP - PERSONAL INVENTORY (Premium) — • Track the components you own • Add quantities, notes, and custom names • Check for missing components before starting a project • Edit and update your inventory anytime — BADGES & LEVELS — • Earn achievement badges as you learn • Reach Bronze, Silver, Gold, Platinum, and Diamond tiers • Track your progress across categories • Stay motivated with gamified learning! — MORE FEATURES — • Push notifications for new projects • Multi-language support (TR, EN, DE, ES, FR, IT) • Favorites and completed projects list • Personal profile and progress tracking BlueGrays is built for the maker and electronics community. Download now and start your electronics journey for free! — SUBSCRIPTION INFORMATION — • BlueGrays Premium unlocks unlimited access to all projects, the full component catalog, and the My Workshop inventory feature. • Payment is charged to your Apple ID account upon confirmation of purchase. • Subscription automatically renews unless cancelled at least 24 hours before the end of the current period. • You can manage and cancel your subscription in Settings > Apple ID > Subscriptions after purchase. • Privacy Policy: https://bluegrays.com/privacy/ • Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

555 Timer & Oscillators Pro

Features
Read full description

Master the design of oscillators and waveform generators using 555 timer integrated circuits, digital logic integrated circuits, operational amplifiers, and transistors. The application provides a comprehensive collection of over 130 tutorials and circuit diagrams, covering 555 timer circuits and practical applications, CMOS 4000 series logic oscillators, TTL 74LS and 74HC series oscillators, operational amplifier–based waveform generators, and transistor multivibrators. Designed for electronics beginners, students, hobbyists, and professional engineers, the app serves as a complete reference and learning tool for designing, understanding, and building oscillators, multivibrators, pulse generators, and waveform circuits commonly used in both analog and digital electronics. In addition to tutorials and schematics, the app includes built-in calculators for frequency, timing, duty cycle, and component value estimation, helping users quickly calculate and adjust circuit parameters. All topics are presented with clear circuit diagrams and detailed explanations. Available in 14 Languages: • English, French, German, Indonesian, Italian, Japanese, Polish, Portuguese, Russian, Simplified Chinese, Spanish, Turkish, Ukrainian, and Vietnamese — study in your native language! Covered Topics: • 555 Timer IC Series • Astable, monostable, and bistable modes • Pulse Width Modulation (PWM) • Voltage conversion circuits • Sensor and external module interfacing • CMOS Logic Oscillators • CMOS 4000 series circuits • Astable, monostable, and bistable modes • Gated CMOS oscillators • TTL / HC Logic Oscillators • TTL 74LS series circuits • 74HC series logic oscillators • Astable and monostable modes • Operational Amplifier Oscillators • Sine wave generators • Square-wave pulse generators • Triangle wave generators • Transistor-Based Oscillators • Transistor-Based Astable multivibrators • Transistor-Based Monostable multivibrators The Pro edition provides additional tools for faster learning and easy navigation: • Full-text search across all lessons and components • Favorites for saving and organizing important topics The content is regularly updated and expanded with each new release, ensuring the latest tutorials and circuit examples are always available.

Screenshots

BlueGrays4 screens
555 Timer & Oscillators Pro4 screens

Verdict

The call

The clearest difference is price: BlueGrays at Free against 555 Timer & Oscillators Pro's $4.99. BlueGrays also leads on update cadence (every 6 days vs every 3 months). 555 Timer & Oscillators Pro's advantage is in-app purchases (none vs 6) and ads (none vs shown). On device support and iOS requirement 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

CostPrice · In-app purchases · Ads · Monetization

BlueGrays is free to download; 555 Timer & Oscillators Pro costs $4.99 up front. BlueGrays sells 6 in-app purchases, starting at $2.99 per month. 555 Timer & Oscillators Pro asks for nothing beyond the download.

UpkeepUpdate frequency

BlueGrays ships an update every 6 days, 555 Timer & Oscillators Pro every 3 months. The most recent releases landed on September 17, 2026 and September 21, 2026 respectively.

Scorecard4 real differences · 6 level
BlueGrays versus 555 Timer & Oscillators Pro: the parameters behind the verdict, then further details
ParameterBlueGrays555 Timer & Oscillators Pro
PriceFree — better$4.99
Rating4.4 (11 ratings) — better—
Positive reviews64.3% of reviews—
Number of ratings11 — better—
Update frequencyEvery 6 days — betterEvery 3 months
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPodiPhone, iPad, Mac — better
Requires iOS15.1 — better16.0
Further details — not scored
Size51 MB22 MB
Age rating4+4+
DeveloperYunus Emre EkeALG Software Lab

In-app purchases

6 purchases

BlueGrays

Subscriptions2
  • Premium (Monthly)$2.991 Month
  • Premium (Yearly)$11.991 Year
One-time4
  • 5x Aylık Eğitimci Paketi$12.99
  • 10x Aylık Eğitimci Paketi$23.99
  • 5x Yıllık Eğitimci Paketi$53.99
Show 1 more
  • 10x Yıllık Eğitimci Paketi$101.99
None

555 Timer & Oscillators Pro

No in-app purchases

Questions

Is BlueGrays free?
BlueGrays is free to download, with in-app purchases available.
Is 555 Timer & Oscillators Pro free?
555 Timer & Oscillators Pro costs $4.99, with no in-app purchases.
Do BlueGrays or 555 Timer & Oscillators Pro have ads?
BlueGrays shows ads; 555 Timer & Oscillators Pro does not.
Which is updated more often, BlueGrays or 555 Timer & Oscillators Pro?
BlueGrays ships an update every 6 days, and 555 Timer & Oscillators Pro every 3 months. Most recently, BlueGrays was updated on September 17, 2026 and 555 Timer & Oscillators Pro on September 21, 2026.

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