The idea!
People need stone fusing, like +ing. Alchemy tools are not rare, like they were months ago, now the extra (sellable!) feature would be stone fusing (blues and attributes).
First of all: A STABLE tool! Sarkoplata did a stable, trustable tool, even if it hasn't got much function apart from +ing.
Free version:
- Read inventory, easy-to-use interface
- Use elixirs
- Use lucky stone, steady stone (not sure if astral/immortal should be in the free one or paid one)
Paid version:
- Free tools' options
- Use attribute stones
- Use magic stones
- Astral and immortal (?)
In my opinion, if it is surely stable and working 95%++ of the time, people would pay some money for stone fusing. And advertising your tool with free version (IF it is stable!) would be a good idea, which has basic features.