Sync My MP3 Beat Splices

I’m putting together a track on an iPhone-based editor and the individual splices keep drifting off-beat. The result is a timing mismatch that ruins the groove. Everything is in MP3 format and, aside from that, the recordings are clean—no pops or artifacts—so the only thing standing between me and a finished mix is getting those cuts to lock in rhythmically.

I need someone who can either:
• take the raw MP3 stems I provide and return a perfectly aligned version, or
• walk me through the exact tap-tempo, grid, or warp-style tools available in common iOS apps (GarageBand, Hokusai, Cubasis, or whichever you know best) so I can keep doing it myself.

Please deliver a bounced, gap-free file plus a short note on what you adjusted so I can replicate the process next time. Quick turnaround appreciated; the song is only a few minutes long.