More detail
The right question is two-part: the language of the app screens, and the language you can get help in. Help and guidance are available in Swahili.
For the in-app interface language specifically, confirm the current options with the team rather than assuming, since interface language is a product detail that can change.
Related questions
Can I get help in Swahili?
Yes. Support and guidance are available in Swahili, and there are Swahili answer pages to help you get started.
Is the app itself in Swahili?
Confirm the current in-app language options with the team, since the interface language is a product detail worth checking for your setup.
Veira gives Kenyan shops one calm app for selling, M-Pesa, KRA eTIMS and stock, with a free terminal. Book a demo and see it set up for your trade.