Twitter enhanced the Campaign creation and monitoring in Twitter Ads to optimize for campaign objectives such as website clicks and App Installs.
Twitter ads that are currently available as Twitter Cards, Promoted Tweets and Mobile App Promotion can be optimized for objectives such as website clicks and conversions.

The enhanced product is currently available for SMBs and API partners and will be made available to other advertisers as mentioned in a blog post on The Twitter Advertising Blog.

The Ads Tool helps advertisers with the defining of objectives, recommending an ad format as well as creating the ad with the help of Image Cropper Tool.

Campaign Monitoring lets you monitor performance for objectives such as website clicks, conversions, Tweet Engagements, App Installs, Engagements, Followers or leads.

The Ads need to be paid for on completion of the action linked to the ad (Cost Per App Click) thereby increasing ROI for advertisers.

Source: Twitter Advertising Blog