Hi @miteshmakwana,

1.  You can use the User Sessions chart and group by device_type: https://help.amplitude.com/hc/en-us/articles/231275508-The-User-Sessions-chart-Track-engagement-frequency-and-duration
2. You can use the Event Seg chart and group by device_type: https://help.amplitude.com/hc/en-us/articles/360033852251-The-Event-Segmentation-chart-an-overview
3. You can use the Retention chart and use the date picker option to toggle between 30/60/90D
4. You can use the Event Seg chart and either group by version of the app, or use the “where” filter to look at number of Uniques for a particular version
5. You can use the Event Seg chart and filter to look at number of Uniques for a particular event
6. You can use User Sessions chart for both 6 and 7!
7. You can use User Sessions chart for both 6 and 7!
8. This is a more complicated question as this is not something that can be done by default within Amplitude.You need to track time spent on their end and then pass in the duration as an event property to any page view type events (such as how long someone spent creating/editing a note). You could then segment and analyze by property metrics like property sum, property average, or property distribution in Event Segmentation.To track duration, you would need to capture the timestamp of a start event and timestamp of an end event, calculate the difference between the two timestamps, and then pass in the duration as an event property for that end event. For example, let's say you have a start event = 'Viewed Home Page' and an end event = 'Clicked Signup'. When the user fires the 'Viewed Home Page' event, you can create a variable in your code called first_timestamp and pass in the current timestamp. When the user is going to fire the 'Clicked Signup' event, you would calculate the difference between the current timestamp and first_timestamp and pass that value into the 'duration' event property. You would then send the 'Clicked Signup' event with the 'duration' event property. This way, you can segment and filter on the value of the 'duration' event property for the 'Clicked Signup' event to see how long it took users to click that button after viewing your home page. I also recommend normalizing the 'duration' event property to a numerical value like seconds so that you can perform functions such as property average in the UI.Here's a potential solution that you could look into to track that.

Regarding your explanation for item 8:

What If I want to measure how much time a user spends in a given page, but "Sign Ups" isn't the only destination a user can chose. 

To the challenge is to measure the time between "View Page X" and leaving for any other page.