I run an non Android OS (Sailfish) that has a compatibility layer that allows the use of Android apps.
Why is it that some apps need access to Google Play Services and some don't? Sailfish doesn't natively support Play Services.
For example HereWeGo and Waze work and have access to location (GPS) on the phone yet Gaspy will not work because it cannot obtain a location. Gaspy doesn't specifically state it needs Play Services but I suspect this may be the cause of the problem with that app and one or two other apps I have had issues getting to work.
Some apps that require Play Services still work but not all functions are available, e.g. Sportstracker which will not display a map but still records the activity which can be uploaded normally.