FlinkSketch is a library designed for implementing sketching algorithms within Apache Flink's DataStream API. It offers several modules, including flinksketch-core for core sketch implementations and flinksketch-bench for benchmarking infrastructure. Users can clone the repository, build it locally using Maven, and create their own Flink applications that utilize these algorithms. The library supports various analytics capabilities, such as approximate frequency counts, distinct counts, quantiles, and identifying frequent items in streams. To set up a project, users need to create a Maven directory structure and a `pom.xml` file that specifies dependencies for flinksketch-core and flinksketch-bench. The article provides a step-by-step guide to create a sample Flink application using CountMinSketch for frequency estimation. Key operations in the application involve ingesting data and querying sketches for specific keys, with example commands to compile and run the project. FlinkSketch supports multiple sketch types, including CountMinSketch, HydraKLL, and wrappers for Apache DataSketches and DDSketch. Each sketch implements the `AggregateFunction` interface, making them compatible with streaming data pipelines. For users interested in benchmarks or examples, the article outlines how to build all modules and run specific examples to understand memory efficiency and frequency estimation in practice. Comprehensive documentation is available for tuning and parameter selection, further aiding users in effectively leveraging the library's capabilities.