"Features as a service" APIs

1. User management

1.1. YesGraph (Referral)

1.2. StormPath

1.3. oAuth.io

2. Search

2.1. Algolia

2.2. Dextro

3. Dashboards

3.1. Keen.io

3.2. Reflect.io

4. Data Enrichment

4.1. Clearbit

4.2. Email Hunter

4.3. FullContact

5. Others

5.1. Textio (TextBox API)

5.2. Picatic (events)

6. Messaging

6.1. Layer

6.2. BuddyCloud

6.3. Imoji

6.4. SendBird

7. geo

7.1. MapBox

8. Social

8.1. TapGlue

9. file management

9.1. Cloudinary

9.2. FileStack

10. eCommerce

10.1. Semantics3

11. Booking / calendar

11.1. Timekit

11.2. Cronofy

11.3. Periodic

12. Voucher

12.1. voucherify