For KOReader (or any other APK) to be installed on a Tolino device, the debug menu has to be enabled:
- if the tolino is on system version 14, search for code
124816
source - if the tolino is on system version 15, search for code
1123581321
source - if the tolino is on system version 16, search for code
112358132fb
source
Note: "searching" as in the search for books on the tolino itself (the magnifying glass in the top bar)