feat: polish app (#669)

src/components/ChainSync.tsx

@@ -0,0 +1,25 @@
+import { ChainState } from '@ethersphere/bee-js'
+import { useContext, useEffect, useState } from 'react'
+import { Context } from '../providers/Settings'
+import ExpandableListItem from './ExpandableListItem'
+
+export function ChainSync() {
+  const { beeApi } = useContext(Context)
+  const [chainState, setChainState] = useState<ChainState | null>(null)
+
+  useEffect(() => {
+    const interval = setInterval(() => {
+      if (!beeApi) {
+        return
+      }
+
+      beeApi.getChainState().then(setChainState).catch(console.error) // eslint-disable-line
+    }, 3_000)
+
+    return () => clearInterval(interval)
+  })
+
+  return (
+    <ExpandableListItem label="Chain state" value={chainState ? `${chainState.block} / ${chainState.chainTip}` : '-'} />
+  )
+}