I am not sure which would suit best, but some kind of password manager would be really handy. 
New: StressMyPC (Dec 10, 2025), Platform 30.1.3 (Nov 17, 2025)
1,400+ portable packages, 1.2 billion downloads
We're close to breaking even this year, please donate today
December 2025 Site Slowdown Being Addressed
KeePass
Been using KeePass for a while now, it works well, no trace left on the pc, just setup the DB in the same folder as the EXE. Might be a possible candidate for PortableApp-ness