Hello Nicole,
In my opinion, if a company uses SAP, it should first look for a solution in SAP. As mentioned above, you can look into netweaver gateway, odata services, sap ui5, SMP..
if you are looking for a cost and time effective way, third party applications can be alternative to you. As Jack's mention, With zMob and www.mysapreport.com you can build an cost effective solution.
With mysapreport you can mobilize existing ALV reports without any modification. To test it just create a ITS restful service (for instructions) and go to www.mysapreport.com , with transaction and an existing variant you can run your reports on mobile. Mysapreport is a iOS web application, if you add it as a shortcut on any iOS device, you can run it in native application look. it is based on jquerymobile so you can run it on iOs, android, blackberry, windows phone, symbian, bada..(Also i run it on LG smart Tv
) it doesn't create selection screen so u can only run reports with variant, at this case zMob maybe be helpful..
if you need any support, don't hesitate to contact me
Regards
Basar Ozgur