Not Free – TruSloMo - Share slow motion video to Instagram, WhatsApp, WeChat. Supports 240fps and 120fps video from iPhone 5S, iPhone 6, iPhone 6+ Review

It doesn't import the original start and stop points for slomo. It applies it's own start and stop points. To adjust requires purchasing.
Review by kw3119 on TruSloMo - Share slow motion video to Instagram, WhatsApp, WeChat. Supports 240fps and 120fps video from iPhone 5S, iPhone 6, iPhone 6+.