Can I run more than one timer at the same time in Kliently?

No — and that's deliberate. Kliently keeps one running timer per workspace. When you start a new timer, the one that was already running stops and saves automatically, so you never end up with two clocks ticking on two projects at once.

This matches how most people actually work: you focus on one thing, then switch. The moment you switch, your previous entry is captured with its hours and rate intact. If you genuinely worked on two things in parallel, log the second block as a manual entry once you're done. See time tracking for the full picture.