For a quick answer to your question.
2. Google Messages
An alternate Google app for your stock SMS Messaging needs.
3. Google E-Mail GMail
Free Google E-mail that gives you upto many gigabytes of space for storing your important E-mails Inbox.
4. Google Play Music
Millions of songs, radio stations, artists, albums by genre, mood, etc.
5. Google Docs
Your online Microsoft office compatible documents i.e Word, Excel and PowerPoint.
6. Google Maps
For real-time GPS navigation, traffic and millions of businesses information nearby.
7. Google Drive
Cloud based free web space for your files, photos, documents, videos, etc.
8. Google Clock
To setup alarms, timer, stopwatch, World clock and many time at many locations.
9. Google Keep
A notes taking application to capture your thoughts, pictures, voice and share with others.
10. Google Keyboard Gboard
This keyboard helps you type by swiping, voice typing and many other cool emoticons.
11. Google Measure
To help you measure physical objects’s sizes i.e. boxes, furniture, spaces etc.
12. Google PhotoScan
Capture glare-free images, crop, straighten and make your images look good.
13. Google Files
Google file manager lets your browse through your phone storage and wirelessly share files with other phones.
14. Google Datally
Manage the limits on your Data bandwidth, hot spot and prevent data limits being wasted.
15. Google Trusted Contacts
Share your real-time location live with your loved ones. This app helps you stay safe.
16. Google Voice Access
Control everything on your Android phone via your voice i.e adjust volume, scroll down a document, enter data without lifting a single finger.
17. Google My Business
If you run your own business, this app will help you not only manage your Google search engine listings, but also help you manage reviews, business profile and helping potential customers connect to you.
18. Google Arts And Culture
It helps you find parks, monuments, local events, tours, etc for via your mobile phone.
19. Google Wallpapers
If the stock wallpapers annoy you, Google offers an awesome collection of wallpaper images.
20. Google Earth
Explore the whole world from above with satellite imagery and 3D terrain of the entire globe and 3D buildings in hundreds of cities around the world.