
Finding tweets by source or device
Twitter reactivated “tweet source label” feature in Dec 2018 :

I was looking at advanced Twitter search page because I needed to search for tweets posted by a specific source.
Also, I found this description on Twitter help without any details on how to use it in search:

Also, a link to list of common third-party sources: https://partners.twitter.com/en/find-a-partner.html
Then I found Twitter search home page with a list of operators can be used in search including tweet source.


Searching by tweet source label
To search for tweets by a specific source, add source: to your search keywords
news source:TwitterFeed Search for tweets containing news and entered via TwitterFeed
To exclude a source, add - before source:
news -source:TwitterFeed Search for tweets containing news and not entered via TwitterFeed
To reveal tweet source on a desktop browser (web), add m. in URL before twitter.com :
https://m.twitter.com/jack/status/1075896805882118144
List of tested sources
I started testing & searching random tweets for sources :
Devices:
- iPhone > source:“Twitter for iPhone”
- iPhone* > source:iOS (used to capture all Tweets sent from within iOS7)
- Android > source:“Twitter for Android”
- iPad > source:“Twitter for iPad”
- Mac > source:“Twitter for Mac”
- Windows Phone > source:“Twitter for Windows Phone”
Twitter Apps :
- Twitter Ads > source:“Twitter Ads Composer”
- Tweetdeck > source:Tweetdeck
- Twitter.com > source:web (the Twitter web)
- Twitter.com > source:“Twitter Web Client”
- Twitter.com > source:“Twitter Web App”
Third-party Apps :
- Hootsuite > source:Hootsuite
- Seesmic > source:seesmic
- Buffer > source:buffer
- IFTTT > source:IFTTT
- SocialFlow > source:SocialFlow
- Epsilon > source:Epsilon
- Instagram > source:Instagram
- Facebook > source:Facebook
- Echofon > source:Echofon
Unknown sources :
These labels are resulting in unrecognized sources
- source:Microsoft
- source:iPhone
- source:Android
- source:iPad
- source:Mac
- source:Linux
- source:apple
Tools to Analysis Profile to find sources
If you want to Analysis sources from one account you can use tools like:

Manipulating the source [Not Tested]
If you are interested in manipulating the source you can use Tweepy API but this will required a twitter developer account.

Is it valuable ?
I was able to use tweet source label in my case to find how my target used his twitter account, he was using Facebook which led me to try to find his Facebook account by searching Facebook using the same words from his tweet .