Are there any web search apps that rank multiple sources in real time?

Yes — there are several kinds of web search apps that do this, depending on what you mean by “rank multiple sources in real time.”

1) General web search engines

These already rank results from many sources in real time or near real time:

• Google Search
• Bing
• Brave Search
• DuckDuckGo (uses multiple sources, though not always its own full ranking stack)
• You.com

2) AI search / answer engines

These often query multiple sources and rank or synthesize them on the fly:

• Perplexity
• You.com AI search
• Phind (more developer-focused)
• Arc Search (summarizes and pulls from multiple sources)
• Genspark / similar “agentic search” tools

3) Vertical / specialized search apps

These rank multiple sources in real time within a niche:

• Reddit search aggregators
• News aggregators like Google News, Feedly, Flipboard
• Academic search like Semantic Scholar, Consensus
• Shopping search tools that compare merchants and rank listings

If you mean “rank multiple live sources side-by-side”

There are also tools that specifically aggregate and score results from multiple engines:

• SearXNG instances
• MetaGer
• Some enterprise search tools with federated search

Quick caveat

“Real time” is usually not truly instant indexing of the whole web. Most systems rank:

• already indexed pages,
• recent crawls,
• or live sources they can query directly via APIs/RSS.

If you want, I can recommend:

1. the best apps for general web search,
2. academic/news/reddit ranking, or
3. apps that let you compare multiple search engines at once.