Meristogenys jerboa — Western Torrent Frog
Some other names for this species:
Gunther’s Borneo Frog, Matang Torrent Frog
This powerful jumper and swimmer inhabits rocky streams in lowland and hillside forests of western Sarawak. These two were near Kubah's waterfall.
I believe these two have enough dark coloration on the snout, tympanum, anterior flanks, etc. to mark them as Meristogenys jerboa rather than the lighter-colored Meristogenys penrissenensis.