Basic interactions, Notifications. No limit on number of steps for dialogue, but gets cumbersome above 5-10 steps.
SMS costs are quite high. Implementers/Users need to be aware
Very basic interaction but doesn’t require literacy (except “Press 5”). Can record messages and allows transfer to a real agent in urgent cases or as fallback.
Call costs can be quite high (especially for outgoing costs). Implementers/Users need to be aware
Basic phone, 2G
Basic interactions. Can support longer interactions Potential timeouts (USSD is like a call).
Complex interactions. Limited offline capabilities are available. Progressive web apps can be installed on a home screen and receive notifications, thus mirroring a lot of native functionality.
Progressive web apps have longer initial load times - though much faster in subsequent loads - and require the development of an app according to specific technologies
Complex interactions. Offline-mode is available with syncing data upon the availability of network connection. Can either be native Android / IOS (probably not that relevant unless for client app) or hybrid.