At the time of development, a developer may need following online services for web development.
- Online Playgrounds – PHP, JavaScript
- Online MySql Database Services
- Code Beautifier services
- SMTP email services
- Disposable email services for testing.
- Blank template for testing.
- CDN for inclusion of various libraries.
- Softwares for local development without internet.
- Saving data, code online for reuse.
- Text utilities
- Image Hosting Services
I suggest options for all these and recommend certain options with reasons.