Sideloading and signing help
AltServer must be running on a computer on the same Wi-Fi; here is AltStore's own checklist.
Five first-install blocks and the fix for each, from Sideloadly's own FAQ.
Apps last 7 days, 3 at a time, and 10 App IDs per 7 days. A paid account removes them.
The "Works today" status threads list the current state and known problems for each tool.
Work down Sideloadly's own error list in order and stop when it works.
Start with the build you run, then the Anisette server, VPN and pairing file.
Signing is blocked on a free Apple ID team. Nobody has an official fix; here is what is known.
Device, iOS version, tool and version, the exact error text, and what you already tried.
A short comparison from each project's own pages, and how to choose.
Two explanations are on the record; we cannot tell which is yours.