RenewSpark Tools vs FolderSure

RenewSpark Tools helps you design safer, more accurate lithium-ion battery packs with clear S/P suggestions, runtime estimates, and real-world build guidance. This update adds dynamic recommendations tailored to power-tool rebuilders, e-bike and high-current builders, car-audio SPL systems, and DIY electronics users. Whether you're rebuilding packs or designing custom battery systems, RenewSpark Tools gives you conservative calculations, practical advice, and confidence in every build.

A finished progress bar tells you the copy ended. It doesn't tell you the copy is correct. FolderSure checks your backup against the original, file by file, byte by byte, using streaming SHA-256 right on your iPad or iPhone. Plug in the card and the SSD, pick the two folders, and know for certain that every photo and every clip made it across intact. One damaged RAW file in 400 GB is invisible until the day you need it. FolderSure finds it and tells you its name. What it does: Verify. Compares source and destination with real checksums. Missing, changed and unreadable files are listed by name, not hidden in a summary. Verified Copy. FolderSure copies the files itself, then reads every byte back from the destination before calling a file done. The safest way to offload a card. Guarded Erase. After a fully verified pass you can delete the verified files from the card. You have to type ERASE, confirm, and the app re-checks every file at the moment of deletion. If anything changed since the pass, it refuses. It never touches files it didn't verify. Re-Verify. Months later, check a drive against a saved manifest and catch bit rot before it costs you a shoot. Resume. Cable pulled or app closed mid-scan? Continue where it stopped. An interrupted job is never reported as verified. Proof you can keep. Export a PDF receipt, CSV manifest, JSON, or a .sha256 checksum file your Mac verifies with a single shasum command. The fine print, in plain words: one-time purchase, no subscription, no account, no ads. Everything runs on your device and the app makes zero network requests. Works with SD cards, USB-C SSDs, USB sticks and any folder the Files app can open. Choose SHA-256 or the faster xxHash64. FolderSure never modifies your source. Verification only reads. The only thing that can delete files is the erase step you unlock yourself after a verified pass. App Review notes (reviewer field): FolderSure needs no account, login or network connection. Everything runs on-device. To test without an external drive: in the Files app, create two folders under On My iPad, put a few files in the first and copy them into the second. In FolderSure pick them as Source and Destination and tap Verify Copy. To see failure detection, edit or delete one file in the destination folder and verify again. The erase feature only appears after a 100% verified pass and requires typing ERASE plus a confirmation dialog. It deletes only the verified files in the user-chosen source folder. The app makes zero network requests. No analytics, no tracking.