About Pocketool
Pocketool collects the free online tools Casper builds, together with notes on the software development, AI assisted work and design behind them. Every tool is built on the same three principles: free, ready to use, and respectful of your privacy.
Your tool pocket
The idea is a pocket with a handful of genuinely useful things in it. Work out a number, tidy up some text, look up an address, or practise speaking English. Whatever brought you here, the hope is that something in the pocket turns out to be the right size for the job.
The otter reaching into the orange pocket is the mascot of this site. It stands for curiosity, quick thinking, and being ready to help. Tools get added over time and existing ones keep changing based on what people report, so each small helper gets clearer and easier to use.
About me
I am Casper, a software engineer who came from visual design, and a co-founder of HexSchool. My degree is in visual design and I started out doing Flash and print work. When responsive web design took off I fell into programming, and through constant self study and sharing what I learned in the community, I gradually moved from designer to engineer.
That route through design is why I am comfortable explaining abstract programming ideas with visuals and everyday comparisons. I believe making a mistake early costs far less than making it later, which is also why I started speaking publicly about technology early, first at local community meetups and later through online courses and teaching.
What I work with
JavaScript, Vue.js, CSS, Sass and SCSS, and responsive web design, along with Node.js on the back end, Docker, deployment, and in recent years AI assisted development as part of everyday engineering practice.
Background
- Co-founder of HexSchool, an online coding school in Taiwan
- Software engineer, previously a visual designer, and an instructor
- Instructor for HexSchool online courses, such as the Vue 3 video course, along with JavaScript interview preparation
- Participant in the iThome Ironman contest for several consecutive years, writing technical articles 30 days in a row each time
- Author of the personal technical blog Casper Blog (in Chinese), whose about page has a fuller background
The tools I make
Each tool's guide page explains what it does and how your data is handled. To browse by category, see all tools. Where each tool's data comes from, which content is AI generated and how mistakes are corrected is set out in the editorial policy and sources; the date and version of every release on each site are recorded in the changelog (in Chinese).
- Pocket Word King: learn TOEIC words and phrases through short games, with audio for every word and no sign-in needed, plus short mock tests in the TOEIC, IELTS and TOEFL question types after signing in (Chinese interface)
- Spinning Top Arena: two-player spinning top battles in the browser
- English Shadowing: shadow English one sentence at a time from YouTube videos
- Speak Cards English Practice: speaking handouts built for real-time AI voice chat
- Emoji and Kaomoji: copy emoji, kaomoji and special symbols in one tap
- Office Life Calculator (formerly Calc Lab): compound growth, annualised return, FIRE, mortgage, pension, leave, overtime and severance calculators
- QR Code Maker (formerly QR Code Studio): QR code and barcode generator
- Taiwan ZIP Code Lookup: 3 and 3+3 digit ZIP codes and English addresses
- Taiwan Life Calculator: financial health and stress self-checks
- Word and Character Counter: Chinese characters, English words and character counts
- Pixel Smith Image Tools: watermark ID copies, convert HEIC photos to JPG, convert WebP or PNG to JPG, blur, pixelate or add text, edit photos online in the Photo Editor and record your screen, with no upload by default
- Device Tester: mouse, keyboard, sound, mic and webcam tests that show what your browser receives or plays
- Office Tools: holiday calendars, date calculations, lunar dates, time zones, table tents, ROC date conversion, garbled CSV repair, list comparison, name masking and email signatures for office administrators in Taiwan, plus a separate Japanese section for offices in Japan (Chinese and Japanese interfaces)
- Chinese Number Converter (a Chinese-language page): write amounts in the formal Chinese numerals used on invoices, receipts and cheques, check them back, work out 5% business tax, or write amounts in English
- Simplified and Traditional Chinese Converter (a Chinese-language page): convert Simplified Chinese to Traditional with Taiwan wording, or back, with every changed word highlighted and subtitle files converted in a batch
Get in touch
Suggestions and collaboration are welcome. The contact page has the channels to reach me. If any of these tools helped, passing them on to someone who needs them is appreciated.
For how data is handled on this site, see the Privacy Policy.
Add this site as a preferred source on Google
If you use Google Search, you can add Pocketool (pocketool.app) as a preferred source in Google's source preferences. According to Google, this tailors your own search experience: when this site publishes fresh content related to what you search for, it becomes more likely to appear in your Top Stories, and in AI Mode and AI Overviews it may be marked as one of your preferred sources. You can untick it on the same page whenever you like.
Site colours
The site uses bright, warm colours while keeping text contrast high:
| Colour | Hex | Used for |
|---|---|---|
| Vibrant orange | #FF6A3D | Logo, buttons and important cues |
| Cream white | #FFFBF6 | Page background and open space |
| Deep cocoa | #352B26 | Text, outlines and weight |
| Misty blue | #D7ECF0 | Supporting blocks and small details |