Some Kiwi VoIP Mobile plans, packs and extras have a Standard Data component and a Fast Data component. This means that each user will have a certain amount of Fast speed data as specified in each user’s plan (for example, 5GB). This is each user’s Fast Data allowance. Once each user has used all their Fast data allowance, they may have Standard Data for the rest of their service period, but speeds will be limited per the plan's definition. This may vary from plan to plan and will impact the user's experience. 

You can continue to message, emails, browsing the web, keeping up on social media, and streaming videos in SD 480p to improve the streaming quality. You may notice an increased load time with viewing videos and images, and if too many apps are open at once, they may not load properly.
The actual speeds you experience will depend on your location, device, network congestion, and other technical factors.