The easiest to find the different things is to check custom charting.
here are all apdex relevant metrics I know of (other=mobile)
|Metric name (as in custom charting)||API key|
|Apdex (by os and geolocation)||builtin:apps.other.apdex.osAndGeo|
|Apdex (by os and app version)||builtin:apps.other.apdex.osAndVersion|
|Apdex (by os)||builtin:apps.other.keyUserActions.apdexValue.os|
|Action count (by os and apdex category)||builtin:apps.other.keyUserActions.count.osAndApdex|
|Action count (by geolocation and apdex category)||builtin:apps.other.uaCount.geoAndApdex|
|Action count (by os and apdex category)||builtin:apps.other.uaCount.osAndApdex|
|Action count (by Apdex category)||builtin:apps.web.actionCount.category|
|Apdex (by user type)||builtin:apps.web.apdex.userType|
e.g. for SaaS use.:
https://[your environment id].live.dynatrace.com/api/v2/metrics/[API key]
And as a heads up, we soon gonna add a web based apdex by geo as well ;).