If you have an iPad/iPhone, look into TouchControl. It's not "dumb", but it can be if you want.

Another approach for a somewhat "dumb" remote that can set relays would be to set relays to indicate the activity that you are controlling. At that point the data sent by the remote is arbitrary and will be translated by OpenHub, based on the current relay settings. Since there is a possibility that things will get out of sync, you might need to re-select the activity from time to time or you could define a "sync" button for each activity on the remote.

Yet another approach would be to define unique codes for each remote key in each activity and simply translate them in OpenHub. There would be only one "activity" in OpenHub -- a huge translate table. If you need to keep track of power toggles, a few of the keys might be macros (functions, subroutines, or whatever they are called in OpenHub) with some logic.