There are a lot of bypass loop switchers with varying degrees of flexibility.
As far as I know, the sound sculpture switchblade, which funnily enough was very recently mentioned in this thread, is the most flexible in terms of allowing changes of loop order, creation of parallel signal chains, and programmable level adjustments between loops. The Boss ES units offer those same capabilities but with some restrictions for parallel paths and internal level adjustments.
Here are some others I'm aware of but know less about:
Morningstar ML5
Voodoo Labs Hex
Decibel 11 Loop Expander
Champion TGC-2
Gigrig Remote Loopy 2
GLabs ML8
RJM mini effect gizmo
Some are small enough to be mounted underneath a pedalboard.