A running log of (small) things I learnt!
CRED hijacks the UPI remarks field to advertise inside GPay’s transaction history - ‘Paid via CRED and got cashback’ shows up in the receiver’s app ▸
UPI transactions have a remarks/transaction note field that travels across the entire UPI ecosystem, as mandated by NPCI. When CRED initiates a payment, it sets this remark to ‘Paid via CRED and got cashback’ - and GPay, PhonePe, or any UPI app simply renders it as-is in your transaction history.
Free smart distribution inside a competitor’s app, similar to ‘Sent from iPhone’ in email signatures.
Uninstalling an app on macOS doesn’t delete all its data - apps like Spotify and Prime Video can leave behind 10+ GB of orphaned data ▸
Unlike windows, macOS has no formal uninstall process - “uninstalling” is just dragging the .app to trash. The OS has no hook to clean up associated data, and app data is scattered across ~/Library/Application Support/, ~/Library/Containers/, ~/Library/Caches/, ~/Library/Preferences/ etc.
I was cleaning up storage with Claude Code and discovered AppCleaner - free and SUPER useful!
If you ‘undo’ a highlight on a Kindle, temporary ghosting remains on the page that only disappears on full page turn. This is because e-ink displays use ‘partial refresh’ for small actions like removing highlights ▸
E-ink pixels are tiny capsules filled with black and white particles that move with electric charge.
A full refresh (the brief black flash on page turns) slams all particles to their correct positions - showing a crisp display. A partial refresh only nudges the changed pixels, which is faster and avoids the flash, but some particles don’t fully migrate - causing that faded/ghosted look.
When you copy an image from Google Docs to markdown, to give ahead to an LLM tool, your context will almost always bloat out. This is because the image gets converted to a massive Base64-encoded data and a single image can blow up into a 15+ page Google doc ▸
Instead of referencing an external URL (), the image’s binary data gets encoded as a long ASCII string embedded inline (). It makes the content self-contained but massively bloated.
Smallest width developer settings on Android let you increase screen real-estate beyond what’s normally possible ▸
A lot of other interesting settings in developer options too, including reducing animation speed that makes the phone so much more snappier.
Bluetooth has a ‘sniffing’ mode to magically connect with switched-off devices ▸
Most Bluetooth devices even when “asleep” can receive your other BT device’s connection request and magically “wake up”. For e.g. your laptop can connect with your switched off bluetooth speaker.
The speaker is in “sniffing” mode where a tiny part of its bluetooth radio is kept on to periodically “sniff” for incoming BT connection requests. A pre-paired device remembers each other’s BT addresses and can therefore connect to each other magically. This also ensures that no non-paired devices can just randomly wake up your bluetooth speaker.
Spotify allows you to paywall podcast access from other subscriptions ▸
Spotify now allows you to paywall protect podcasts with real time info-sharing of your subscriptions on other platforms. E.g. this NYT podcast that is only accessible to NYT subscribers, with in-app authentication possible on Spotify to vet your subscription status.
Your Mac has a built-in job scheduler! ▸
Knowing this means you can potentially “program” your laptop to do X things at Y time of the day every Z days. This fact, merged with Claude Code Skills, effectively means you can setup complicated workflows in a recurring manner all natively on your Mac, with no need to access any server based service like n8n, github actions etc.
There are 2 built-in job schedulers in Mac: Cron and Launchd. Cron will miss stuff out if your laptop is “off” at the time of the job. Launchd can queue in stuff so even if a job is missed, it will re-activate the next time your Mac wakes up.